FREE BIOLOGY AND STUDY GAMES ABOUT BIO101 CHPT

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FREE BIOLOGY AND STUDY GAMES ABOUT BIO101 CHPT

13 EXAM QUESTIONS

Actual Qs and Ans Expert-Verified Explanation

This Exam contains:

-Guarantee passing score -74 Questions and Answers -format set of multiple-choice -Expert-Verified Explanation

Question 1: Organisms that possess homologous structures probably _____

Answer:

share a common ancestor that also had this structure Question 2: All known organisms use genetic information to produce protein molecules via the same genetic code. This finding strongly supports the hypothesis that _____.

Answer:

all organisms are descended from one or a few common ancestors Question 3: The forelimbs of humans, cats, and bats have a number of detailed similarities in their construction. What best explains these similarities?

Answer:

The forelimbs are similar because all of these organisms inherited the basic forelimb design from a common ancestor Question 4: According to the Hardy-Weinberg principle, the frequencies of alleles in a population will remain constant if _____ is the only process that affects the gene pool.

Answer:

sexual reproduction

Question 5: Each of us is part of the ongoing evolution of the human species. Which of the following forms of microevolution is currently most important in human populations worldwide?

Answer:

Global travel and migration are promoting gene flow on an unprecedented scale.

Question 6: A population is _____.

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a group of individuals of the same species occupying a given area Question 7: Sickle-cell disease is a debilitating disease that results from being homozygous recessive for the "sickle-cell allele" of a hemoglobin gene. Why is the allele present and even common in many human populations?

Answer:

The sickle-cell allele confers malaria resistance to heterozygotes. In some regions where malaria is common, heterozygotes have an advantage, and their reproductive success maintains the recessive allele at a high frequency in the population.Question 8: Which best describes how an organism's Darwinian fitness is measured?

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the organism's reproductive success relative to other individuals in the same population Question 9: Which of the following would seem to be an example of neutral variation?

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human fingerprint patterns Question 10: Which of the following statements best describes how the process of natural selection works?

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Better-adapted individuals will leave behind more offspring to carry on their genes, producing a dynamic "fit" between a population and its changing environment.Question 11: Blue poppies native to China are grown at a plant-breeding center in California, where those with the thickest leaves survive and reproduce best in the drier climate. This evolutionary adaptation of the poppies to their new environment is due to ____

Answer:

directional selection

Question 12: Critics sometimes claim that the theory of evolution is flawed because it is based on random changes: mutations. They say that a random change in an organism is likely to harm it, not make it function better. What statement refutes these critics?

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Mutation is random; natural selection is not Question 13: Biologists often use the term fitness when speaking of evolution. Below are descriptions of four male grizzly bears. According to your understanding of evolution, which bear would biologists consider the most fit?

Answer:

Sandy Question 14: Approximately one out of every 2,500 Caucasians in the United States is born with the recessive disease cystic fibrosis. According to the Hardy-Weinberg equilibrium equation, approximately how many people are carriers?

Answer:

• in 25

Question 15: To be successful in evolutionary terms, an organism must _____.

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pass its genes on to the next generation Question 16: How does the overuse of antibiotics in medicine and agriculture contribute to a major public health threat?

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Indiscriminant use of antibiotics selects for resistant bacteria.Question 17: Birds with average-sized wings survived a severe storm more successfully than other birds in the same population with longer or shorter wings. This illustrates _____.

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stabilizing selection Question 18: An important challenge to traditional ideas about species was the observation that seemingly dissimilar organisms, such as hummingbirds, humans, and whales, have similar skeletal structures. This most directly suggested to biologists that _____

Answer:

dissimilar organisms might have evolved from a distant, common ancestor

Question 19: Which of the following is a true statement about Charles Darwin?

Answer:

He proposed natural selection as the mechanism of evolution.Question 20: A geneticist studied a grass population growing in an area of erratic rainfall and found that plants with alleles for curled leaves reproduced better in dry years, and plants with alleles for flat leaves reproduced better in wet years. This situation woul

Answer:

preserve the variability in the grass population Question 21: What broad set of ideas was established by the work of Lamarck, Lyell, and Darwin?

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Earth and its life are ancient and ever-changing; fossils document the evolution of life-forms over time.

Question 22: Fossils are most likely to be found in _____.

Answer:

sedimentary rock Question 23: The severe reduction in genetic variability seen in the endangered cheetah is probably attributable to _____.

Answer:

having gone through at least one bottleneck

Question 24: Which best describes the fossil record?

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The fossil record is the highly ordered sequence in which fossils are found in layers of sedimentary rock.Question 25: In natural selection, _____ determine which phenotypes are successful.

Answer:

current conditions in the local environment Question 26: Mutation plays a large role in the microevolution of bacterial populations. Why?

Answer:

Bacteria multiply very rapidly, and they are haploid so that a mutant allele will immediately have a full effect on the phenotype.